1. Field of the Invention
The present invention relates to an air-conditioning apparatus and in particular to an air-conditioning apparatus for a vehicle.
2. Description of the Related Art
The increasing popularity of sports utility vehicles (SUVs), which are substantially longer than ordinary passenger cars, has led to the installation in SUVs of air-conditioning apparatuses for supplying air, a stream of cool air for example, to the center and rear seats of the SUV, that is, to the second and third row of seats.
FIG. 4 is a perspective view showing an example of such an air-conditioning apparatus. As shown in FIG. 4, an air-conditioning apparatus 50 has a ceiling duct 52 provided on a ceiling VC of a vehicle V for supplying conditioned-air, for example, a stream of cool air, and four vent grilles 54 provided on the ceiling VC to communicate with the ceiling duct 52. The direction of the air blown from the vent grilles 54 is adjustable. The ceiling duct 52 extends along the ceiling between the center seats and the rear seats from the left to the right of the vehicle. FIG. 5 is a bottom view of the ceiling duct 52. As shown in FIG. 5, the four vent grilles 54 include two front vent grilles 56 and two rear vent grilles 58. The front vent grilles 56 and the rear vent grilles 58 include right vent grilles 56R, 58R and left vent grilles 56L, 58L. As shown in FIG. 4, the air, such as a cool air stream, conditioned by an air conditioner unit 60 provided at the rear VB of the vehicle V is led to the ceiling duct 52 along the side VS of the vehicle V and flows through the ceiling duct 52. The cool air stream flowing through the duct is blown into the compartment VR of the vehicle V through the vent grilles 56, 58. The cool air stream is blown forward from the front vent grilles 56 and the cool air stream is blown rearward from the rear vent grilles 58. Since the blowing direction of the cool air stream is adjustable by the vent grilles 56, 58, passengers sitting in the center and rear seats are able to change the direction of the cool air stream to direct it to their own faces.
The above-mentioned air-conditioning apparatus 50 has the drawback that when passengers sitting in the center and rear seats adjust the direction of the cool air stream during operation of the apparatus 50, the flow speed and volume of the cool air stream blown from the vent grilles 56, 58 may become larger or smaller. For example, when the blowing direction from the vent grilles 56, 58 is directed toward the right, the air flow speed and volume can be maintained relatively large because the cool air stream flowing from the ceiling duct 52 extending from the left to the right is blown toward the right without changing its flow direction. On the other hand, when the blowing direction from the vent grilles 56, 58 is directed toward the left, the air flow speed and volume may be relatively small because the flow direction of the cool air stream flowing through the ceiling duct 52 from the left to the right is turned around by approximately 180 degrees to allow the cool air stream to be blown toward the left. Therefore, there is a problem in that passengers sitting in the center and rear seats are not able to adjust both the direction and the flow speed and volume of the cool air stream at the same time.
Further, in the above-mentioned air-conditioning apparatus 50, the cool air streams are blown from the front vent grilles 56 toward the back of the heads of the passengers sitting in the center seats. Since it is preferable for a cool air stream to be blown onto the face, passengers sitting in the center seats of the vehicle equipped with the air-conditioning apparatus 50 are not able to get a satisfactory cool feeling.
Further, since in the above-mentioned air-conditioning apparatus 50 the ceiling duct 52 extends from the left to the right in the lateral direction of the vehicle, the flow speed and volume of the cool air stream blown from the right vent grilles 56R, 58R tends to be smaller than that blown from the left vent grilles 56L, 58L. Therefore, the amount of cool air a passenger receives is likely to differ depending on whether he or she sits on the left side or the right side of the center and rear seats.